Spark-plug



A. B. KINZEL.

SPARK PLUG.

APPLICATION FILED JULY 11. 1919.

Patented Apr. 19, 1921.

Will!!! UNITED STATES PATENT: OFFICE.

aueusrus :a-x'inznn, or new YORK, N. Y.

' sunk-Para. 1

To all 'whom it may concern:

Be it known that I, Aocus'rus B. KINznL,

a citizen of the United States, and a resident of the city of New York, county of New York, and State of New York, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a specification.

The present invention relates to internal nection with the drawing forming part thereof.

Figure l-is a view in side elevation of a spark plug constructed in accordance with the invention;

. Fig. 2 is a central sectional view of the same;

Fig. 3 is a top plan view thereof; and

Fig. 4 is a bottom plan vi ew.

In the construction illustrated, the spark plug comprises a bushing 1, having a hexagonal head 2 and a threaded bodyportion 3, as usual. The bushing has an lnternal annular flange 4 engaged on opposite sides by plugs 5 and 6 of insulating materiah,

These plugs are mounted on an electrode 7 positioned axially within the bushing and extending therethrough. The washer 8 held in place by a pin 9 thereupon and a pair of nuts 10, 11, one serving as a lock nut-for the other, serve as suitable means cooperating with the electrode 7 to clamp the two insulating plugs firmly against the upper and lower sides of the flange 4, thus making a tight oint. The lower plug 6 is illustrated as made of mica. Such plug must be carefully made to present a smooth surface against the smooth lower face of the flange to insure a tight joint. Other materials may be used but mica is preferred for the reason that the carbon which ordinarily is deposited against the cylinder head does not adhere to mica for which reason whenmica is used frequent cleaning of the plug is rendered unnecessary. The upper plug 5 may be of any suitable insulating material. I

Specification of Letters Patent.

Patented Apr. 19, 1921.

Application filed July 11, 1919. Serial No. 310,081.

prefer to use bakelite which is found to be particularly well adapted for this use.

One of the insulation plugs is reduced and shouldered at its end to fit within the annular flange to reduce or eliminate the space between the two plugs. As shown, the lower plug is reduced and shouldered as indicated at 14. The upper plug 5 is shown as fitting into a recess 15 in the bushing and agalnst the flange 4, this construction servmg to firmly hold the plug5 in position.

Preferably, a washer.l6 of a compressible insulating material such as asbestos or the like, is introduced between the plugs in order to avoid the necessity 'of either makmg the plugs and flange with great accuracy and yet to avoid the difiiculty of hav I surrounded by an insulating material 18 to prevent short circuit between the bushing and electrode. The material used in accordance with the present invention is soft and yielding to prevent breaking when accidentally struck with tools and the like. It may be sufliciently rigid so that 'it can be unscrewed from the electrode when taking apart the plug or may be soft and adhesive since it is not necessary that the plug should be taken apart for cleaning. The insulation 18 consists of a relatively soft gutta percha compound or of a bituminous material, reinforced b a fabric embedded therein or inclosing t e same, as indicated at 19.

The terms upper and lower and the like, are herein used as referring to the spark plug when in the position shown in mounted onthe electrode within the bushing and engaging the lower end of said flange, and an msulatin plug mounted on the electrode engaging tie upper side of said flange, means onsaid electrode and cooperating therewith to clamp the two plugs against the op osite Sides of said flange and a relatively soig yielding insulation surrounding said electrode above the insulating plugs having a fabric reinforcement.

2. A spark plu comprising a bushing having an interna annular flange near its upper end an electrode axially positioned in said bushing, an insulating plug of mica mounted on the electrode within the bushing and engaging the lower end of said flange, and an insulating plug mounted on the electrode engaging the upper side of said flange, means on said electrode and cooperating therewith to clamp the two plugs against the opposite sides of said flange, a compressible insulating washer between said insulatin plugs, and a relatively soft yielding insu ation surrounding said electrode above the insulating plugs having a fabric reinforcement.

3. A spark plug comprising a bushing having an interna annular flange near its upper end, an electrode axially positioned in said bushing, an insulating plug of mica mounted on the electrode within the bushing and engaging the lower end of said flange, and an insulating plu mounted on the electrode and engaging tie upper side of said flange, means on said electrode and cooperating therewith to clamp the two plugs against the opposite sides of said flange, and a relatively soft yielding insulation surrcliunding said electrode above the insulating p ugs.

In testimony whereof I have hereunto, set my hand.

AUGUSTUS B. KINZEL. 

